I've had the KelTek for a while and never had any problems with it. It shoots well and has never jammed or anything.
The KelTek is a little bit smaller than the Ruger. Not much though. I think they weigh about the same.
Here is a pic together:
Sorry about the quality. It's pic off of my phone.

I put a few rounds thru it yesterday and was pretty impressed with it. Shot 50 rounds in all. Shot at this target for the first 10 rounds. These shots were taken from 16' away. 8 out of the 10 were on the paper, and one hit the very top of the target. The other shot was just off of the target high and too the right.

Very happy with the gun. No misfires at all. Does have quite a bit of recoil. You could shoot it with one hand, but it would be difficult to hit anything. And it's extremely LOUD, must wear earplugs while practicing.
Anyway here's the target. Keep in mind, I'm no marksman! LOL